Read EPUB books online

Read EPUB books online

EPUB is the open standard for e-books, used by Apple Books, Google Play Books, Kobo, Nook, public-library apps and countless free sources such as Project Gutenberg and Standard Ebooks. Normally you need a reading app to open one. This reader opens an EPUB right in the browser tab on a Windows PC, Mac, Chromebook, Linux machine, tablet or phone, with the book's own layout, fonts and images, a table of contents and the controls you expect from an e-reader – and the file never leaves your device.

How to use it

1. Drop an EPUB file (or a DRM-free MOBI, AZW3 or FB2).
2. Pick a chapter from the contents list or page through with ‹ and ›.
3. Change the text size, turn on night mode or search the whole book.
4. Optionally download the book as EPUB to keep it in your library app.

Reader features

Formats it opens

• EPUB 2 and EPUB 3 – reflowable books from any publisher or converter.
• MOBI and AZW3 (KF8) – DRM-free Kindle-format books are converted to EPUB in the browser first, then shown in the reader.
• FB2 and FBZ – FictionBook files popular for Russian and Eastern European literature.
• Books protected with DRM (Adobe ADEPT, Kindle store, Apple FairPlay) cannot be opened, because the text is encrypted for authorised apps only.

Why read in the browser

A browser reader is handy when you cannot install software – on a work or school computer, a library PC, a borrowed laptop or a Chromebook – or when you just want to check a file before importing it. Authors and self-publishers can preview an EPUB they built in Sigil, Calibre, Vellum, Pages or Word to make sure the chapters, images and table of contents look right before uploading it to a store. Teachers can open course texts without asking students to install apps.

Privacy and safety

The EPUB is unpacked in memory on your device. Chapters are displayed in a sandboxed frame with scripts disabled, so a book cannot run code, track you or reach other pages; images, stylesheets and embedded fonts are loaded from temporary local addresses that disappear when you close the tab. Nothing is uploaded, and no copy of the book is stored on a server.

How an EPUB is built

An EPUB is a ZIP archive. A small file called container.xml points to the package document (OPF), which lists every file in the book (the manifest), the reading order (the spine) and metadata such as title, author and language. The chapters themselves are XHTML pages styled with CSS, much like a website. The reader follows the same steps an e-reader does: it opens the archive, reads the package, builds the table of contents and displays the chapters in order.

Tips for comfortable reading

• Use full screen (F11 on Windows and Linux, Ctrl+Cmd+F on Mac) to remove distractions.
• Increase the text size on phones, or zoom the page with pinch gestures.
• Night mode reduces glare in the dark; combine it with your device's night light.
• Search for a character's name to find where they first appear.
• For long books, keep the tab open – your position is remembered if you come back to the same book in this browser.

Limitations

Fixed-layout EPUBs (children's picture books, comics and some textbooks) are shown, but pages may not scale as precisely as in a dedicated app. Audio and video overlays are not played, and scripted interactive content is disabled for safety. Some MOBI files contain images in Kindle-only formats that cannot be shown; their text still appears. Annotations and highlights are not saved.

Related conversions

To turn the book into a printable document, convert it with EPUB to PDF. If you have a Kindle book you want in a different format, use MOBI to EPUB, and for AZW3 files use AZW3 to EPUB. To read a PDF instead, open the PDF Reader.

Works with almost any PDF

The tool opens PDFs from Word, Google Docs, LibreOffice, scanners, phones and design software, including PDF 1.0–2.0 files with forms, annotations and embedded fonts. Files protected with an *open* password must be unlocked first with Unlock PDF (you need the password); files that only have permission restrictions usually open directly. Large documents with hundreds of pages work too – the limit is your device's memory, typically several hundred megabytes on a laptop and around 100 MB on a phone.

Windows, Mac, iPhone and Android

There is nothing to install. It runs in Chrome, Edge, Firefox and Safari on Windows, macOS, Linux, ChromeOS, Android and iOS. On a phone, tap the drop area and pick the file from Files, Google Drive or your e-mail downloads; the result is saved to Downloads or the Files app and can be shared straight to WhatsApp, Gmail or Drive.

Common problems and fixes

• "File is encrypted" – remove the open password with Unlock PDF, then try again.
• The file is a cloud placeholder – download it fully from OneDrive, iCloud or Drive first.
• A damaged or truncated download – run it through Repair PDF.
• Very slow on a phone – large scanned PDFs need lots of memory; close other tabs or split the file with Split PDF first.
• The download did not start – some in-app browsers (Instagram, Facebook) block downloads; open the page in Chrome or Safari.

Combine it with other PDF tools

Most jobs take more than one step, and every Fileopia tool works the same way, so you can chain them without uploading anything. A typical workflow: scan or convert the pages, merge them into one file, put them in order with Organize PDF, make scanned text searchable with OCR, add page numbers, and finally compress the result for e-mail. Each step downloads a new file and leaves your original untouched, so you can always go back and try different settings. Tip: give each output a clear name such as *contract-signed-compressed.pdf* so you can tell the versions apart later.

Privacy

Everything happens inside your browser tab with pdf-lib and PDF.js. The PDF is read from your disk into memory, processed there and saved straight back to your device. It is never uploaded, stored or logged, and the tool keeps working offline once the page has loaded – which makes it suitable for contracts, medical records, HR files, bank statements and anything else you would not e-mail to a stranger.